Richtmyer-Meshkov Instability in the Turbulent Regime

We investigate the Richtmyer-Meshkov instability in the turbulent regime with three-dimensional random interfacial perturbations. Experiments are conducted on the Nova laser with strong radiatively driven shocks $(\mathrm{Mach}>20\mathrm{})$ in planar, two-fluid targets. The mixing zone at the interface is found to increase in time as $h\sim t^{\beta }$ with $\beta \sim 0.6\pm 0.1$. Hydrodynamic simulations in 2D obtain similar values of $h$ over the observation time, but with a larger exponent. A heuristic turbulent impulsive model is offered to identify the underlying processes.